RELATIONS PERTAINING SIMPLE [BOOK ]. 



Q 



K sin (lL) cos (/ Z) 



* 



r 

 -JTJ tan p tan B 



tan b = p 



n. By putting .ZV= X, we shall make 



and we shall have, 



tan (/ A) = -- 



^ = _ _?_ _JL_ 



r &quot; sin (I J.) cos (/ J.) 



r&amp;gt;/ 



tan j3 p tan 5 



tan b = r , - . 



T 7 



HI. By putting N= % (X -f- _Z/), / and // will be found by means of the 

 equations 



tan U (X -f- X)j =: r , _ -, tan i (X L) 



and afterwards 5, by means of the equation given above. The logarithm of the 

 fraction 



r R 



-7- 



TV 



is conveniently computed if -7- is put = tan f, whence we have 



In this manner the method HL for the determination of / is somewhat shorter 

 than I. and II.; but, for the remaining operations, we consider the two latter 

 preferable to the former. 



